The present invention relates in general to a pre-maxillary implant, and more particularly to an implant device to be surgically inserted in the pre-maxillary area of the face to increase the protrusion of the base of the nose, adding support to this area by increasing the mask of the pre-maxilla.
One of the unfortunate consequence of primary rhinoplasty can be the formation of an excessively retruding or acute naso-labial angle due to columellar retraction. This in turn causes loss of, or failure to achieve proper tip projection. The real basis for this is lack of protrusion of the whole nasal base which consists of alae, base of nostrils and columella.
Since the nasal base rests on the pre-maxillary area, i.e., the upper base of the alveolar processes between the pyriform apertures and alveolar eminences, attention to this area is necessary for successful primary and secondary rhinoplastry. Augmenting this area is certainly nothing new. Over 25 years ago Aufricht described the use of cartilage grafts of silicone implants behind the upper lip together with a columnellar "orthopedic" suture which also narrows the nostrils. Guerro-Santos has recommended a similar procedure. Hindered has devised an implant inserted by extending the transfixion incision to section the Depressor-septi-nasi muscle. Carroni has proposed a transversely inserted step-like silicone implant with the highest step at the columella-labial angle.
The present invention is a novel pre-maxillary implant to be introduced in the sublabial area, designed to achieve improved protrusion of the nasal base and in turn producing proper tip projection. This implant configuration pays particular attention to increasing the protrusion of the boney foundation of the nasal base, i.e. the pre-maxillary area, to properly support the tip and very importantly the laterial alae. If this is not achieved, then the various techniques previously proposed for top projection, such as the Goldman tip, L-shaped implants, shield grafts, bunching sutures, etc. can achieve only limited success at best, and at worst fail to achieve desired results. It is essential that proper foundation from below be provided for the tip to be projected above.
The causes of improper tip projection fall, like everything else into two broad categories: heredity and environment. Within the scope of the latter are trauma, infection or iatrogenic causes such as excessive reaction of the candal end of the cartilegeous septum, improper management of the membranous septum, excessive resection of the alar cartilages or removal of the anterior nasal spine. Within the scope of heredity are a retracted lower base of the nose found more commonly in the non-caucasian. In some patients, the retroposition of the maxilla along with a posterior and inferior inclination or absence of the anterior nasal spine produce a prognathic facial appearance which if severe is called, most unattractively, an "ape lip" deformity. Since the growth of the maxilla is achieved by advancement and resorption of the bone in these directions, it is not difficult to see how these "deformities" result. In others, this appearance is due to a decreased dental-axial angle in relation to the anterior nasal spine. This angle, as described by Schule as between the upper central incisors and the anterior nasal spine plane to be considered aesthetically normal is 70.degree. (seventy). This is combined with a retroposition of the upper alveolar process and sometimes with a short columella thus increasing the retrusion of the nasal tip. If the maxilla is severly retruded, a long flat lip with a gummy smile can result. Also this causes the melolabial fold to be closer to the alar groove and therefore more accentuated.
While wrestling with the problem of tip projection, after experiencing my share of failures both in primary and revision surgery, I became increasingly aware that the real problem was lack of protrusion of the entire base of the nose and support had to be added to this area by increasing the mass of the pre-maxilla. Many times enough cartilage was not present from grafting and small pieces of silicone did not work well since these were placed only at the feet of the mesial crura and accurate suturing was sometimes difficult. In some individuals, I was able to harvest an adequate cartilage graft from the the xiphoid process of the sternum. This has distinct advantages over costal or costochondral grafts.
I therefore consider that these problems can be alleviated by providing a specially designed and configuration implant, for example, of semi-solid silastic, having a central riser or upright pedestal portion for support of mesial crura with a groove to insert a strut, if needed, and a 70.degree. posterior inclination. The pedestal portion is provided with a posterior notch to provide fit against the anterior nasal spine, and thinner lateral extensions project to either side for normal nostril contour. Posterior extensions are provided for support of lateral alar bases. This is inserted using the sub-labial approach under the DSN muscle to provide a foundation for nasal base protrusion and tip projection.
Other objects, advantages and capabilities of the present invention will become apparent from the following description, taken in conjunction with the accompanying figures illustrating a preferred embodiment of the invention.